"""
72. 编辑距离
"""


class Solution:
    def minDistance(self, word1: str, word2: str) -> int:
        n, m = len(word1), len(word2)
        # 有一个字符串为空串
        # if n * m == 0:
        #     return n + m

        # DP 数组
        dp = [[0] * (m + 1) for _ in range(n + 1)]

        # 边界状态初始化
        for i in range(n + 1):
            dp[i][0] = i
        for j in range(m + 1):
            dp[0][j] = j

        # 计算所有 dp 值
        for i in range(1, n + 1):
            for j in range(1, m + 1):
                left = dp[i - 1][j] + 1
                down = dp[i][j - 1] + 1
                left_down = dp[i - 1][j - 1]
                if word1[i - 1] != word2[j - 1]:
                    left_down += 1
                dp[i][j] = min(left, down, left_down)
        return dp[n][m]


# class Solution1:
#     def minDistance(self, word1: str, word2: str) -> int:
#         m = len(word1)
#         n = len(word2)
#         dp = list(range(n + 1))
#         for i in range(m):
#             lu = dp[0]
#             dp[0] = i + 1
#             for j in range(n):
#                 dp[j+1], lu = min(dp[j]+1, dp[j+1]+1, lu+int(word1[i] != word2[j])), dp[j+1]
#         return dp[-1]


if __name__ == '__main__':
    x = Solution()
    print(x.minDistance('', '中国a'))
